Gary Dederich, 66, worked for many years as a registered nurse at a hospital in the Denver area and was taking a vacation in Washington, D.C.

At approximately 6:02 p.m. Tuesday, units from the Fourth District responded to the 800 block of Emerson Street, Northwest, for the report of an unconscious person. Upon their arrival, they found Dederich, suffering from blunt force head trauma.

Metropolitan Police Lt. Robert Alder says Dederich was killed near the rental property he had been staying in for the past two weeks while on vacation.

Alder says the murder did not occur in a tourist area.

"We are looking into the potential that it was an attempted robbery," Alder said. "I cannot remember the last case that we had ... where any tourist was the victim of a homicide in Washington."

D.C. Fire and Emergency Medical Services personnel responded to the scene and Dederich was later pronounced dead by a member of the Office of Chief Medical Examiner.

Dederich lived two blocks from the University of Denver, in a well-kept home on a corner lot.

"Yeah, it's a little quaint house. If you look at the way he kept his house and his yard, he had a lot of self worth," friend and neighbor Chris Razzazian said.

Dederich was a retired registered nurse who worked at Swedish Medical Center in Englewood, according to friends and a background check.

"Gary lived his life as well as any person could," Razzazian said.

Gary's life ended in northwest D.C., a few miles from the national landmarks he was there to visit as a tourist.

"He was definitely a very well-traveled man," Razzazian said.

Dederich gave his time to A Little Help, a nonprofit in Denver that empowers senior citizens to stay in their homes as they get older, just like he did.

Executive Director Dr. Paul Leon Ramsey says clients would request Dederich, known for his kindness and compassion as a volunteer.

"After he retired as a nurse he spent a significant amount of time caring for his neighbors and folks who didn't live right in his own neighborhood," Ramsey said.

Neighbor Danny Beckett says he'll miss having Dederich around.

"I think it's a tragedy. It's just not fair," Beckett said.

Razzazian says his friend, 40 years his senior, was always out in yard and waving hello no matter who was passing by him.

"He never let a generational gap get in between a conversation or communication. We always talked about how nice it was that we could see over the fence so that we could see each other," Razzazian said.

Metropolitan Police asked Denver Police for help notifying Dederich's next of kin.

Neighbors never saw family or visitors stop by the house.

"He was really a very private person," Razzazian said.

Neighbors described Dederich as an asset to the neighborhood and someone they're sad to see go.

"The people that you live around are the people that you live your life with. And you need to know your neighbors," Razzazian said.

Neighbors say Dederich was never married and had no children. They were not aware of any memorial plans.

The Metropolitan Police Department is offering a reward of $25,000 for information which leads to the arrest and conviction of whoever is responsible for Dederich's murder.

Anyone with information about this case is asked to call the police at 202-727-9099. Additionally, anonymous information may be submitted to the department's TEXT TIP LINE by text messaging 50411.